This research project is concerned with the immunochemical study of lens proteins in normal and pathological states. The ability of alpha crystallin subunits, depending on their ratio, to assemble into alpha crystallin or into molecules with a different quaternary structure will be further studied. The potential role of variation in the assembly of alpha crystallin subunits in cataract formation will be investigated. The investigations of normal lens proteins will involve analysis of the distribution of antigenic determinants on different subunits of alpha crystallin. Immunochemical probes will be used for the determination of molecular changes on SH-containing or SH-free subunits of alpha crystallin, e.g. with age and cataract. Such studies may be extended to include also other lens crystallins. Investigations of complex formation resulting from lens protein-protein interaction and its dependence on age and cataract is an additional objective. The organ specific properties of the lens proteins make them uniquely suited for research on auto-immune responses. Such investigations will be continued and include studies on the mechanisms of lens-induced uveitis. Investigation of the mechanism of cataractogenous changes will be mainly concerned with changes in the molecular structure of lens proteins as well as changes of lens protein-protein complexes associated with the loss of lens transparency and the relation of such changes to the one in changes in aging. Further immunochemical studies involve evolutionary development at the molecular level. These studies are based on the direct conclusion from the evolutionary theory that common antigens in the lens of different modern species must have been derived form their common ancestor. The aim of this research is to analyze the structural alterations of individual lens proteins following evolutionary development.